Search My Blog

Loading...

Monday, April 23, 2012

Everything About Enzymes!! (and a free lab!)

Recently, I was required to attend a system-wide inservice meeting for all the science teachers in our district. In attendance were science teachers of grades 7 through 12. These events are fun and interesting, mostly because I have been teaching for 28 years, and it is nice to see science teachers from other schools that I have known for years, but rarely get to see. After joining up with a group of old acquaintances, the inevitable question came up: "What have you been doing in your biology classes?"

I responded with, "I have just finished teaching a unit on enzymes to our biology 1 students." One of the other teachers immediately responded with, "I don't really teach that in my class."

What???? How do you NOT teach about enzymes in a biology class???? As soon as I returned home that day, I promptly sent her all of my teaching materials on enzymes.

Enzymes are the stuff of life. No cell would be alive without the action of enzymes. Life in a cell is made possible through the hundreds of chemical reactions that occur there. If these chemical reactions proceed too slowly, the activities of the cell would come to a screeching halt. You see, enzymes are biological catalysts. They speed up the chemical reactions of the cell. Without these enzymes, the reactions of the cell would proceed so slowly that they would be of no use to the cell, and the cell would die.

When is the best time to teach about enzymes? I begin teaching about enzymes when I teach biochemistry. When teaching about carbohydrates, lipids, and proteins, it is a natural fit to talk about enzymes as you discuss the structure and functioning of proteins. I also teach about enzymes when I cover photosynthesis, respiration, replication, transcription, digestion..... This list could go on and on since enzymes are involved in every single biological process!

Be sure to cover all the basic points about enzymes:

Enzymes are biological catalysts that speed up the chemical reactions of the cell.

Enzymes are proteins.

Enzymatic reactions occur faster and at lower temperatures because enzymes lower the activation energy for that chemical reaction.

Enzymes are never consumed or used up during the reaction. They can do their job over and over again.

Enzymes are highly specific for just one substrate. The enzyme has an active site with a unique 3-D shape into which this substrate must fit.

Enzymes catalyze both the forward and the reverse of the same reaction.

Enzymes can be denatured by temperatures and pH levels outside the optimal range for that particular enzyme.

Enzymes are truly amazing proteins that play a vital role inside every living cell. Please don't leave this out of your curriculum!

Okay.... I did promise you a freebie. This is a lab that I have done for years, and it remains a favorite with my students year after year.